Written by Bennett Kirschner
How Abandoned Offshore Rigs are Changing the Gulf of Mexico
Hundreds of feet below the Gulf of Mexico’s surface, there’s a network of bustling underwater cities. They are built on the skeletons of offshore oil rigs that have long since been abandoned by their owners, but remain seated on the Gulf’s floor. Colonies of mussels, encircled by swooping schools of fish, now obscure the steel frames that once towered above the seafloor and held up platforms where oil workers labored day and night.
“When you look at a map of the Gulf of Mexico, it looks like a thumbprint,” says Richard Charter, a writer and political consultant who has researched American offshore drilling policies since the 1980s. Charter is talking about the winding mess of oil pipelines, wells and rigs that are scattered across the muddy bottom of the Gulf, and on maps resemble the undulating grooves of a fingerprint. They make up an intricate infrastructural network that extracts petroleum from the Gulf floor, sometimes thousands of feet beneath the surface of the water, and then transports that crude oil to the web of refineries sitting along the Gulf Coast.
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Although offshore drilling was little more than a concept in 1947, the federal policymakers who originally defined its regulations weren’t naïve. They knew that every offshore rig, like anything else, living or not, would eventually meet its expiration date. With this in mind, they made sure that each offshore rig built in American waters came with a simple guarantee from its owner – any rig no longer in use would have to be removed, and the seafloor over which it stood would be restored to its original ecological state.
The process this entailed, called decommissioning, has since been performed on thousands of rigs in the Gulf and requires several steps which today cost millions, sometimes even tens of millions, of dollars (Charter, et al. 10). First, the vertical pipelines which connect the above-sea platform to the well are severed, usually about 15 feet below the seafloor, and filled with coagulate material. The well is considered plugged once a thick layer of concrete is poured over this, ensuring that any residual oil won’t leak from the vestigial pipes. The platform is either dismantled or moved to another drilling site, and the jacket – the soaring metal structure resembling an electrical tower which reaches from seafloor to surface to prop up the platform – must be towed to shore, where it will either be repurposed or melted for scrap (10, 39).
The 1954 policy that required decommissioning was called “Idle Iron” and seemed like an adequate defense against any risk of derelict rigs disturbing the Gulf’s ecological equilibrium. If the oil companies would clean up after themselves, the Gulf – expansive, shimmering – could maintain its natural integrity, despite the ecological disruption that active rigs may cause. The oil industry was starting to put down its roots in a frantic influx of construction – the Gulf would be home to over 4,000 active platforms by 2004 – but it was only able to do so on the grounds that its trash would not be deserted on the seafloor (9-10).
But between the 1950s and the 1960s, an extraordinary development started to challenge the terms of this agreement. Throughout the Gulf, recreational fishermen had begun spotting vibrant marine communities that had made homes out of active rigs’ jackets – “people noticed there were good places to fish almost right off-the-bat,” says Mike McDonough, Louisiana’s Artificial Reef Coordinator (McDonough). By the 1970s, about half of all fishing trips in the Gulf traveled straight to offshore rigs, where flourishing biological communities of small and large fish alike could be harvested (Jørgensen 347). Fishermen would tie their boats to a rig jacket, cast their nets, and return to shore hours later with hauls up to 50 times larger than those they were accustomed to having in open waters (347). And though it had come as a surprise that the Gulf had amassed the world’s largest assortment of artificial underwater habitats, its origin wasn’t much of a mystery to those looking back (Charter, et al. 9).
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Since the floor of the Gulf of Mexico is naturally muddy and flat, the types of productive, concentrated habitats where fishermen could pull in lucrative hauls of fish like groupers and red snapper were practically nonexistent in the 1940s and 1950s. Marine life, though plentiful, was spread out across a vast underwater plain, meaning fishermen had to work long, arduous shifts just to return to shore with modest hauls (Jørgensen 346, 352).
For this to change, the habitat needed more complexity – as long as the Gulf floor remained flat and muddy, it could never provide the concentrated marine populations that recreational fishermen desired. They wanted to be able to capture more fish by covering less territory with each dropped net, but nothing other than habitable surfaces with vertical structure could provide what they needed (Kilson, et al. 1069-1070). Since vertical structures have some parts that are closer to sea level and others that are closer to the seafloor, they could provide many different levels of light, allowing a variety of species with diverse needs to thrive in one place (1072-1073).
Fishermen along the Gulf coast had been lobbying for the government to lay abandoned ships or concrete slabs on the Gulf of Mexico floor to create artificial reefs (Jørgensen 346). By providing the type of physical surface, called substrate, which was porous and rigid enough for corals to take hold, these materials would offer something that a flat seafloor could not. Corals, mussels, clams and algae would congregate on the substrate, they argued, and this would attract commercially viable fish like red snapper and generate the types of productive fisheries that the Gulf of Mexico lacked (348).
And although the soaring metal jackets of the rigs installed in the 1940s and 1950s provided the topography that fishermen wanted, the idea that they could become a viable habitat for corals seemed absurd at the time. The columns and cross-braces of the jackets’ legs provided plenty of substrate, to be sure, but their slick, narrow surfaces were untenable; just like a person cannot climb up a glass window, there was no way that coral could adhere to the jackets’ steep-sloped steel.
But this assumption, though right in principle, failed to account for a mix of other critters – the pioneer species, like tube worms, mussels and clams – that could stick to smooth vertical surfaces, and which would provide the type of substrate that other species could latch onto (Fariñas-Franco, et al. 75-76). Shortly after the rigs started being installed in 1954, these species began colonizing the jackets before any other species could, and this was enough to jumpstart the biological communities that inhabit the rigs to this day.
Here’s how the process works: over the course of many generations, the husks and shells of the pioneer species accumulate on the metal columns’ surfaces, creating a rockier, more porous substrate that corals can latch onto. As the corals grow, they secrete their own hard skeletons onto the columns, which are already covered by a thin film of discarded exoskeletons. The buildup of this material over several generations increases the complexity of the substrate, rendering the legs no longer uniform and smooth, but craggy and porous (Kilson, et al. 1072-1073).
By this point, the rigs are full-fledged coral reefs – the unscalable metal beams, now covered by a thick coat of generations of sea life, seem more like aquatic rock-climbing walls than industrial infrastructure (France 105-106; Manoudis 211-214; Fariñas-Franco, et al. 90-91). Small fish flock to the rigs, where they can deposit their eggs on the cross-beams and feed from the abundance of algae and coral, and the larger fish follow close behind (Kilson, et al. 1069-1070). Together, these lifeforms create the basis for a diverse, self-sustaining population of marine life that flourishes in the unlikeliest of places.
By the 1970s, then, the fishermen’s wish had been granted in the form of these teeming communities, and marine biologists, buoyed by the power of retrospect, had no trouble explaining what had happened since the rigs started popping up in the Gulf 20 years before (Ajemian, et al. 12-13, 17-18; Syc, et al. 458-459, 463-466). The creatures of the Gulf, once dispersed over wide swaths, were now huddling in cities that rose hundreds of feet above the seafloor – as early as 1984, scientific studies showed that these aquatic metropolises provided over a quarter of the Gulf’s hard bottom habitat (Jørgensen 345). Almost none of these studies, though, sought to ask whether the jackets were helping produce life or simply assembling it into concentrated communities that were ideal for fishermen, and therefore conducive to overfishing (Charter).
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Soon after the fishermen started flocking to the rigs, oil companies saw an opportunity not to be missed: in the absence of any opposing science, the abundant communities surrounding the jackets and the eager fishermen who came to meet them offered a heartwarming image that could offset any popular impression of oil companies as greedy behemoths. In the early 1980s, companies like Phillips Petroleum started running ad campaigns that showed fishing boats nestled contentedly against rigs while touting platforms in the Gulf of Mexico as “part of an ongoing plan...to not just take from the earth, but to give back as well” (qtd. in Jørgensen 343). Respected newspapers like The Wall Street Journal meanwhile started taking note, publishing articles that lauded the rigs as “oases...in underwater deserts” (355; Sterba 1).
The political traction that came from this positive media attention could not have come at a more convenient time for the oil industry. Many of the rigs installed in the 1950s were approaching their anticipated expiration, meaning that soon, oil companies would have to spend millions of dollars on decommissioning obsolete rigs (348). But if the federal government could be convinced to alter the terms of the Idle Iron policy and allow some of the rig jackets to be left in the ocean by virtue of their status as productive marine habitats, the oil industry could curtail decommissioning expenses by millions of dollars.
In 1986, Congress granted the industry’s request, ratifying the “Rigs-to-Reefs” policy, which allowed disused jackets to be left in the Gulf on the grounds that they provided “a national resource of tremendous public and private value” (qtd. in Jørgensen 347). Today, over 500 retired rigs sit off the Gulf Coast, with 392 in Louisiana waters alone. Some rest on their sides like sleeping giants, and others have had their top 85 feet removed so that they can remain upright while large boats pass above (Charter, et al. 10, 55).
The process of “reefing” pares down the decommissioning procedure so that it is significantly cheaper: the wells are still plugged up, and the platform is removed, but instead of towing the jacket hundreds of miles back to shore, the rig jackets – some of them as tall as 1,500 feet, eclipsing the Eiffel Tower – are either left in place or moved a much shorter distance to a state-designated reefing zone (Charter et al. 86-88). The company must then donate half of its declared savings to a state-run Artificial Reef Fund devoted to maintaining and monitoring the artificial reefs. Mike McDonough, whose job as Louisiana’s Artificial Reef Coordinator wouldn’t exist without the fund, says the donation is intended “to prevent the appearance of ocean dumping, and ensure that the rig operators really have some skin in the game” (McDonough).
But could it be that the petroleum industry’s bottom line and the health of an entire ecosystem really line up as flawlessly as the oil industry and federal government have suggested for years? Is it possible that a program which, according to conservative estimates, has saved oil companies over $90 million, is an unquestionably good thing for the Gulf’s ecology (Charter etal, 87)?
Richard, who has been studying the Rigs-to-Reefs program since its inception, firmly believes that the abundant natural life dwelling on and around the converted jackets belies an essential truth – the artificial reefs are not creating new life, he claims, but rather, attracting biomass which already exists. “Listen,” Richard tells us, “I know of No – with a capital N – peer-reviewed, objective science...that can demonstrate that the rigs support primary production. Yes, they attract fish, and yes, you can go catch them, but they are not producing biomass” (Charter). The evidence we have, he argues, suggests that virtually all of the life on the rigs would have existed regardless of the jackets’ presence in the Gulf, and that the high concentrations of fish around the converted jackets have caused overfishing of species such as red snapper (Charter, et al. 26, 98).
Richard’s objections, though, are largely falling on deaf ears – the Rigs-to-Reefs program in the Gulf of Mexico seems to be dying a natural death, and will probably continue without a hitch until it finally comes to a quiet standstill. Today, there are a little over 2,000 active rigs in the Gulf, and “about 200 are removed each year,” Mike tells us. “Rig installations are fewer than a handful each year,” he adds, meaning it will probably be a little over ten years before Rigs-to-Reefs applications stop coming in altogether.
“Lately, we’ve been getting about 10-12 artificial reef applications per year,” he says, noting that this number, which was as high as 30 in 2007, has probably plummeted because most derelict rigs are so far from reefing zones that the projected cost of reefing offsets any potential savings on decommissioning (McDonough). A few more traditional jackets will be converted to reefs in the next few years, and then there will be a period of relative silence in the Gulf’s Rigs-to-Reefs program – “we can see the [program’s] twilight, I guess,” Mike says.
Drilling in the Gulf, though, is far from over – companies are switching from traditional rigs to deepwater, “floating” ones, almost all of which are extremely productive and expected to last for several more decades. But who’s to say what will happen in twenty to thirty years, when many of these rigs will reach the ends of their lifespans? So far, only one has been decommissioned, and a major piece of it – the spar, a 400-foot long tube-shaped structure designed to protect vertical pipelines – was towed to a reef zone and deposited on the seafloor (McDonough). “The owner of the rig didn’t know how to get the spar into port, or how to get it out of the water and into a barge,” Mike says, “so towing it to a reef site was going to be cheaper.”
The Rigs-to-Reefs program in the Gulf may or may not have a renaissance down the line, but its legacy is clear: coral and fish have made homes out of hundreds of abandoned jackets, and oil companies and fishermen have reaped the benefits. Though the question remains whether the jackets provide valuable habitats or just offer a convenient excuse for corporations to dump their trash, their presence has profoundly altered the Gulf of Mexico, and will continue to for years to come.
